Staple



p 1944- w. DRQYPOLCHER 2,357,637

S TAPLE Filed Jan. 6, 1942 2 Sheets-Sheet l v i .7- y 1 T 36 Z INVENIITOR W14 04M 5 n 04 095/? ATTORNEY W. DRYPOLCHER Sea 5, -1

S TAPLE Filed Jan. 6, 1942 2 Sheets-Sheet 2 INVENTOR ATTO RN Y Patented Sept. 5,1944

STAPLE William Drypolcher, Valley Stream, N. Y., assignor to Lou Obstfeld, Brooklyn, and Abraham Obstfeld, New York, N. Y.

Application January 6, 1942, Serial No. 425,711

11 Claims.

This invention relates to staples, and more particularly to bars or sticks of staples used in magazine-type staple'drivin machines.

The primary object of my invention is to generally improve staples and staple bars. A more particular object is to form staple bars without the need for bending and sharpening individual staples and subsequently sticking the same together in bar form by means of an adhesive.

Another object is to manufacture staple bars quickly and cheaply, a considerable number of complete bars being formed simultaneously if desired. Still another object is to make staples and staple bars that are rust-proof. A further object is to make staples and staplebars of any desired color.

With these objects in view I have successfully experimented with the use of non-metallic materials, specifically molded plastics, and have found that these materials, contrary to normal expectation, may be used for staples, even for "tacking, that is, for driving into wood or pulp board or like solid materials. With many moldstaple bars may be molded in each operation of the machine.

Another advantage of moldedstaple bars arises in connection with so-called racked staples. The use of ordinary metal staples in racked formation is disclosed in Patent No. 1,811,060. When racked staples are molded in bar form, the staples may be made substantially thicker than equivalent sheet metal staples, thus strengthening the plastic staples, yet the staples may be received in and used with a conventional staple driving machine originally designed for use with metal staples. To obtain this desirable result constitutes another feature and object of my invention.

To the accomplishment of the foregoing and such other objects as will hereinafter appear, my invention consistsin the staple bar, and method of making the same, as well as their relation one to the other, as hereinafter are more particularly described in the specification and sought to be defined in the claims. The specification is accompanied by drawings in.which:

Fig. l is a partially sectioned plan view of a short length of staple bar embodying features of my invention; I

Fig. 2 is a side elevation ofthe same;

Fig. 3 is a section taken approximately in the plane of the line 33 of Fig. 1;

Fig. 4 is a partially sectioned front elevation of the staple bar;

Fig. 5 is a perspective view of a single staple;

Fig, 6 is a section through a mold cavity for' molding my improved staple bar;

Fig. 7 is a similar section through a mold cavity for a slightly modified staple bar;

Fig. 8 schematically illustrates a. die for simultaneously molding four staple bars;

Fig. 9 is a fragmentary view schematically showin the center portion of a die for molding a much larger number of staple bars;

Fig. 10 is a horizontal section through the staple magazine of a, staple driving machine loaded with a staple bar made in accordance the staple legs, and these edges are preferably' sloped or chisel-shaped, as is best shown in Fig. 4. The staple bar is further provided with transverse score lines or grooves defining the legs and bridge of the individual staples, in order to facilitate shearing the successive staples from the bar as they are being driven by a staple driver. Scorings or grooves l6 and I8 are preferably provided on both the inside and outside of the side walls 20 of the bar. These grooves are preferably made relatively deep, leaving a minimum of material between the adjacent legs so that the legs will be relatively freely separated when th staple is driven. In the specific staple bar here illustrated, the bridge portion or top wall is scored at the top only, as is illustrated by the score lines 22. In this way a greater amount of connecting material is left between the adjacent staples, thus strengthening the bar against accidental breakage durin handling. The extra material to be sheared is located at the top of the bar where the staple is directly engaged by the staple driving blade. In this way there is no tendency to bend the staple, such as might result if. a substantial amount of material were left between adjacent staple legs.

The staple bar may be molded in a mold having one or more cavities, and Fig. 6 schematically represents a section through one such mold cavity. In that figure the cavity is formed between upper and lower mold parts 24 and 26, which meet on a parting surface 28. Sloping surfaces formed on the upper mold at 30 provide the desired sharpened or chisel-shaped ends for the legs. parts are provided with ridges 32 and 34 which form the score lines orindentations between adjacent legs. The lower mold part 26 is also provided with ridges 36 which form the indentations across the top of the staple bar.

Referring now to Fig. 8, a single die 40 is provided with four cavities, 4'2, 44, 46 and 48, said cavities being connected to a, central gate 50. It will be understood that this illustration is merely schematic, and that in practice the mold will comprise separable halves which fit, together in the manner illustrated in Fig. 6, the ejector half having the usual ejector pins, and ejection of the complete molded piece including the gate and connecting branches, etc. Aligning pins and temperature regulating means, etc., have also been omitted.-

Fig. 9 schematically shows how a larger and more elaborate die may be'used for the simultaneous molding of a large number of staple bars, It will be understood that each of the four main branches has been broken away in Fig. 9, and may actually extend further until there is anywhere from one to two dozen staple bars on each branch. In this figure, as in Fig. 8, details such as the ejector pins, aligning pins, etc., have been omitted, in order not to unnecessarily complicate the drawings.

It has been pointed out that in the staple bar shown in Figs. 1 through 4 the indentations between the bridges of the successive staples are on top of the bar. They may, in fact, form a continuation of the outside scorings for the staple legs. The resulting staple may be like that shown in Fig. 5, it comprising legs I connected by a bridge Hi. The legs are bevelled at all four corners, while the bridge is bevelled at the top corners.

The indentations at the bridge may, however, be on the bottom, in which case they may form a continuation of the inside scorings for the legs, and such modification is shown in Fig. 12. This is a section similar to Fig. 3, but differs in showing a staple bar having a smooth top, with score lines 52 on the lower side of the bridge.

Of these two modifications I prefer that shown in Fig. 3, because any slight roughness or irregularity resulting during the shearing of the successive staples, will appear at the bottom or inside of the staple bridge when using the arrangement shown in Fig. 3, but is apt to appear on the outside or exposed top of the staple bridge when using the arrangement shown in Fig. 12.

The bridge, like the legs, may be scored on both sides, and such an arrangement is shown in Fig. 13. This is a section similar to Fig. 3, but the bridge of the staple bar has upper score lines 54 and lower score lines 56. This is in some respects an advantageous construction, in that it provides the bridge of the staple with smooth bevelled corners. It may not be amiss to point out, however, that it is preferable to use deeper scorings for the legs than for the bridge, even with the arrangement of Fig. v13. In fact, the scorings for the legs may be made as deep as possible until they substantially meet, because Both the upper and lower mold" to six degrees.)

material between opposite scorings will usually be adequate at the legs.

As so far described, the staples may be disposed perpendicular to the length of the staple bar. The specific staple illustrated in Figs. 1 through 4, however, has the staples disposed at an angle. (The angle has beenerraggerat'ed for clarity. In practice it is a matter of only three Staples formed of flat wire have been cemented into bar form in angular relation, the said staples being known in the trade as racked staples. Such an arrangement is disclosed in U. S. Patent No. 1,811,060, issued June 23, 1931. Many staple driving machines are already on the market designed for use with these racked staples. In such machines the staple driving blade is disposed. at the proper angle for mating relation with the 'endmost staple. These machines'are therefore not well adapted to use ordinary staples disposed perpendicular to the bar, but can use a staple bar of the type here shown. 1 i

It will be understood that the only change needed to make racked staples when practising my present invention, is to appropriately change the configuration of the mold cavities. This change has not been illustrated in Figs. 8 and 9, but it will be understoodthat it is merely necessary to dispose the ends of the cavity at the desired slight angle, and to similarly angularly dispose the transverse ridges which form the grooves.

For adequate strength, a staple made of a molded plastic may be made with thicker legs than would be the case with an equivalent metal staple. This may be done even when using racked staple machines already on the market, because the legs of the molded racked staples are disposed at an angle to the bridge, or parallel to the length of the staple. This will be clear from inspection of the staple legs shown in Fig. 10, and is to be contrasted with the staple legs 62 shown in Fig. 11, which represent the stepped or racked relation of sheet metal staples, In Figs. 10 and 11 I show a horizontal section through a staple magazine 64 having a staple core 66 with staple channels 68 therebetween. These channels are designed to receive the racked staples of Fig. 11 with a desired clear-' ance. It will be evident from inspection and comparison of Figs. 10 and 11 that while maintaining the same clearance between the staple legs and the side walls of the channels 68, the staple legs may be substantially thicker in the arrangement of Fig. 10 than in the arrangement of Fig. 11. This results from the fact that the legs in Fig. 10 lie parallel to the channels, whereas in Fig. 11 they are disposed at an angle to the channels.

even a few thousandths of an inch thicknes 9i When th legs are thickened as above described, the top or bridge of the staple may also be thickened, if the stapling machine is one having ample or exaggerated clearance on top. If, however, the stapling machine has a limited clearance on top, the bridge of the staple may be left unthickened. Such a staple is illustrated in Fig. 14 in which the staple legs are thicker than the bridge 82. In many respects this is a scientific staple design, because the thrust when driving the staple is taken by the legs, and there is a tendency to bend the legs under the pressure of the staple driver. The staple driver, however, bears against the entire length'of the bridge of the staple, and this need not be as strong against bending as the legs. With conventional metal staples made of bent wire, there has been no convenient way of making a staple with the legs thicker than the bridge, but with my present method of molding the entire staple bar, it is an easy matter to mold the staples (whether racked or not) with differences in thickness as illustrated.

It is believed that the method of making and using my improved molded non-metallic staple bar, as well as the many advantages thereof, will be apparent from the foregoing detailed description. The staple bar is stronger than a cemented bar of metal staples, thus leading to less waste and less bother from the need of loading broken pieces. Moreover, broken pieces sometimes wedge in the feed channels of the staple driving machine and cause operating difliculties. Because no adhesive is used there is no difficulty from peeling off of adhesive. When adhesive peels on in excessive amounts it is apt to jam up .the operating channels of the machine. (Government specifications on staples take th precaution of guarding against excessive adhesive.)

Staples may be made in different colors. Colors can be selected by the user to match the materials being stapled. The entire bar of staples may have a lightly indicated trade-mark, or other form of identification, molded on its surface. The staples are rust resisting and noncorrodible, without using strategic metals. The staples may be made cheaply because of their method of manufacture, alarge number of complete staple bars being made in a single stroke of a. molding press. The staples are light in weight, with consequent saving in shipping cost. The staples may be molded with a bevel or other desired type of point as a direct part of the original molding operation, no special sharpening operation being needed. Moreover, there is a saving in the usual cost for sharpening or/and replacement of the tools employed to bevel or to sharpen the wire staples. In the case of racked staples, a thicker staple leg may be used without any change in the magazine of the staple machine. The legs and bridge of th staples may be made different in themselves.

The material used for making the staple may vary. Plastics may be used, such as the phenolics, the ureas, the acetates, the polystyrines, etc. Natural as well as artificial resins may be used. Hard rubber may also be used.

. It will therefore be apparent that While I have shown and described my invention in a preferred form, changes and modifications may be made without departing from the spirit of the invention, as sought to be defined in the following claims. In the claims I have for convenience employed the term plastic, but this is intended 3. A staple bar for a stapling machine comprising a single integral trough-shaped piece of molded non-metallic plastic material, molded to trough shape, the said staple bar being adapted for use in a magazine type staple driving machine, said bar being provided with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver of the staple driving machine, there being less material left between staples at the legs than at the bridge.

'4. A staple bar for a stapling machine comprising a single integral trough-shaped piece of molded non-metallic material, molded to trough shape, the said staple bar being adapted for use in a magazine type staple driving machine, the exposed longitudinal edges of said bar which correspond to the ends of the staple legs being sloped or chisel-shaped, and said bar being provided with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver of the staple driving machine, said scorings being provided on the inside and outside of each of the side walls of the bar, so that the leg portions of the staple are relatively freely severable from the staple bar.

5. A-staple bar for a stapling machine comprising a single integral trough-shaped piece of molded plastic material, molded to trough shape, the said staple bar being adapted'for use in a magazine type staple driving machine, the exposed longitudinal edges of said bar which correspond to the ends. of the staplelegs being sloped or chisel-shaped, and said bar being provided with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver of the staple driving machine, said scorings being provided at least on one side of the bridge and on the inside and outside of each of the side walls of the bar, so that the leg portions of the staple are relatively freely severable from the staple bar. there being less material left between staples at the legs than at the bridge.

6. A staple bar for a stapling machine comprising a single integral trough-shaped piece of a molded plastic material, molded to trough shape, the said staple bar being adapted for use in a magazine type staple driving machine, said trough-shaped molded bar being provided with transverse scorings delineating the legs and bridge of the individual staples and defining the shearing lines for shearing each staple from to include equivalent materials such as hard rubher and other materials that may be molded.

I claim:

1. A staple bar for a stapling machine comprising a.single integral trough-shaped piece of molded material, molded to trough shape, the

said staple bar being adapted for use in a magal zine type staple driving machine, said bar being provided with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver of the staple driving machine. I

2. The staple bar of claim 1 in which the scoring defined legs are of different'thickness than the scoring defined bridge of the individual staples of the bar.

thebar as the staple is being driven by a staple driver of the staple driving machine.

7. A staple bar comprising a single integrally molded trough-shaped piece of molded material, said bar being provided. as a part of the molding operation with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver, the

scorings for the bridge portion or top wall being disposed at an angle to the side walls, thereby making the staple bar usable in stapling machines designed for use with racked staples.

- 8. The staple bar of claim 7 in which the scoring defined legs are of different thickness than the scoring defined bridge of the individual staples of the bar.

9. A staple bar comprising a single integrally molded trough-shaped piece of molded non-metallic plastic material, said bar being provided as a part of the molding operation with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver, there being less material left between staples at the legs than at the bridge, the scorings for the bridge portion or top wall being disposed at an angle to the sidewalls, thereby making the staple bar usable in stapling machines designed for use with racked staples.

10. A staple bar comprising a single integral trough-shaped piece of molded non-metallic material, the exposed longitudinal edges of said bar which correspond to the ends of the staple legs being sloped or chisel-shaped, and said bar being provided as a part of the molding operation with transverse scorings'defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver, said scorings being provided on the inside and outside of each of the side walls of the bar so that the leg portions of the staple are relatively freely severable from the staple bar, the scorings for the bridge portion or top wall being disposed at an angle to the side walls, thereby making the staple bar usable in stapling machines designed for use with racked staples, the thickness of the staple being greater than that of an equivalent sheet metal racked staple without, however, requiring increased clearance in the channels of the staple magazine, the flat sides of the legs of the staples being disposed parallel to the sides or the staple bar and at an angle to the bridge of the staple.

11. A staple bar comprising a single integral trough-shaped piece of molded plastic material, the exposed longitudinal edges or said bar which correspond to the ends of the staple legs'being sloped or chisel-shaped, andsaid bar being provided as a part or the molding operation with transverse scorings defining the legs and bridge of the individual staples to facilitate shearing each staple from the bar as the staple is being driven by a staple driver, said scorings being I provided at least on one side of the bridge and on the inside and outside of each of the side walls of the bar so that the leg portions of the staple are relatively freely severable from the staple bar, there being less material left between staples at the legs than at the bridge, the scorings for the bridge portion or top wall being disposed at an angle to the side walls, thereby making the staple bar usable in stapling machines designed for use with racked staples, the thickness of the staple being greater than that of an equivalent sheet metal racked staple, without, however, requiring increased clearance in the channels of the staple magazine, the flat sides of the legs of the staples being disposed parallel to the sides of the staple bar and at an angle to the bridge of the staple, and the legs of the staple being disposed perpendicular to the plane of the top or bridge of the staple bar.

WILLIAM DRYPOLCHER. 

